Cisco Reports New Vulnerabilities

Cisco Systems is reporting that two of its key security products, the Cisco VPN 3000 Concentrator and much of its firewall line, could be vulnerable to attack.

The two vulnerability reports and forthcoming patches are unusual for Cisco, which unlike Microsoft, has only issued one other security advisory since the end of May. Cisco even challenged a vulnerability presented at the Black Hat conference last month. (See Black Hat Flaw Eludes Cisco.)

Cisco says it does not know of any attacks yet that exploit the bugs, "although we are aware that some customers have been impacted" by the firewall software bug."

The firewall vulnerability, which was discovered by Terje Bless from Norwegian research house Helse Nord IKT, affects most of Cisco's product line, including the Cisco PIX 500 Series, the ASA 5500 Series, and the Firewall Services Module embedded in the Catalyst 6500 switches and the 7600 Series routers. The flaw, which involves an automated password change, could allow intruders to access these devices, or it could lock administrators out, the company says.

"The software issue may cause the EXEC password, passwords of locally defined users, and the enable password in the startup configuration to change without the user's intervention," Cisco says. The flaw could prevent administrators from logging into the device if authentication is configured to use the passwords stored in the startup configuration, the company says.

Cisco has promised to issue a software patch for the problem, but it is not available yet. The company is offering a configuration workaround that eliminates the vulnerability. The company did not give details on the problems reported by its customers, so there's no way to be sure whether they were hacked or simply locked out.

On its VPN 3000 Concentrator, Cisco has discovered two vulnerabilities that could allow an attacker to change or create a directory via a flaw in the FTP function. Using this flaw, an attacker might be able to "perform network reconnaissance" or change the configuration of the concentrator by renaming or deleting configuration and certificate files, Cisco says.

The vulnerability, which was reported initially by the NCC Group, has been patched. Users can obtain the patch from Cisco's Website, or they can use one of several workarounds that limit FTP access to the concentrator, eliminating the bug's potential impact. Cisco says it has not seen any exploits that exhibit the vulnerability.

In his advisory on the SANS Institute's Internet Storm Center, security expert Daniel Wesemann suggested that the new vulnerabilities are relatively unlikely to have been widely exploited. "Why anyone would want to allow FTP to their VPN concentrator escapes me."

— Tim Wilson, Site Editor, Dark Reading